Physics of Force
This invention is based on a branch of physics known as classical mechanics. Classical mechanics deals with the natural laws of motion, and is often associated with the ground-breaking work of Sir Isaac Newton. Newton, working in the late 17th and early 18th Centuries, realized that for every force exerted on a body, there is an equal but opposite reactive force. Imagine someone who pushes a shopping cart while standing on roller skates. Experience tells us that the cart will move forward and the person pushing the cart will tend to roll backward in the opposite direction. This is an everyday example of the principle that every action has an equal and opposite reaction.
This principle is the basis for all manner of propulsion, including walking, jet travel and rocketry. For example, a rocket propels itself through space by expelling matter in the form of burning propellant. The expulsion of matter through the tail of the rocket creates an equal but opposite force (or "thrust") that propels the rocket forward in the desired direction. A more common illustration is the toy balloon that is inflated and released. The balloon will careen about the room as the air inside is expelled through the nipple. The air acts as a propellant, just like the fuel in a rocket.
The principle is equally applicable to terrestrial vehicles. In a motorboat, the turning propeller forces water toward the boat's stern, propelling the boat forward. In a jet plane, the jet engine forces air and fuel toward the rear of the plane, creating thrust that moves the plane forward. In a car, the motive force is applied by the friction of a spinning tire on the road surface.
For each mode of transportation, the force or thrust pushing the vehicle forward is the result of an action-reaction force interchange (e.g., propeller against water). Key to this process is the existence of some external mass (such as water, air, road surface or discharging rocket fuel) against which the vehicle may impart a force. As Newton tells us, this force pushes the external mass in one direction, and the vehicle in the opposite direction, thereby propelling the vehicle as desired.
The energy of a moving vehicle such as a car, jet or bicyclist is called "kinetic" energy. Vehicles use on-board engines (such as automobile motors, jet engines, and even the human body) to convert the "potential" energy in fuel (such as gasoline or food) into kinetic energy. Specifically, the consumption of fuel is used to move the engine (often in a rotating direction). The movement of the engine is converted into movement of the vehicle via a prop (in the case of a boat or plane) or drive transmission (in the case of a land vehicle).
Terrestrial Propulsion Problems
On Earth, there is usually no shortage of external mass (such as water, air, or ground) against which a vehicle or other object may be propelled. Nevertheless, there are situations where there is no convenient external mass to provide propulsion. For example, the tip of a very tall tower tends to vibrate and sway (or "oscillate") in an undesirable manner because there is nothing but air to anchor the tip of the tower. The tower tip is in effect a moving body (like a vehicle), whose motion we are interested in stopping. We would like to provide propulsive force in the opposite direction of the tower's movement to stabilize the tower. Conceivably, one could place propellers on opposite sides of the tower, and use the thrust generated by the propeller to stabilize the swaying tower. However, this solution would be expensive, energy-consumptive, and otherwise wholly impractical.
Towers are usually stabilized by using guy wires to anchor the tower tip to the ground. This solution often limits the height of the tower, and, in the case of large towers such as office buildings is not practical or aesthetically acceptable. When guy lines cannot be used, the tower must be built with sufficient strength and rigidity to avoid swaying under normal loads (such as high winds). Unfortunately, earthquakes and other events may impose extraordinary loads on the tower, causing dangerous oscillation and eventually structural failure. Ideally, there would be a practical way of dampening oscillation by applying a motive force to the tower tip in the opposite direction of oscillation.
Extraterrestrial Propulsion Problems
Vehicles in space exhibit three broad classes of motion: oscillatory, rotational and linear. Oscillatory motion is a back and forth or vibratory motion such experienced by large flexible spacecraft undergoing attitudinal correction. Rotational motion is the spinning movement of a body, such as a space station or satellite rotating about its central axis. Linear motion is the straight-line movement of an object traversing between two points in space, such as a rocket accelerating away from the Earth and toward the moon.
Unlike our environment here on Earth, outer space is a vacuum--that is, a place devoid of any mass against which a body could propel itself. For example, an astronaut on a space walk would be unable to move relative to his or her ship if the tether connecting the astronaut were severed. Even with arms flailing and legs kicking, the astronaut could not propel him or herself back to the ship, or even so much as control the direction which he or she was facing. It is impossible to "swim" through space as one does through water because there is no mass in space against which to propel oneself.
Because space is a vacuum, a vehicle that will move through space in a controlled manner must bring along its own external mass in the form of propellant which is discharged to provide moving thrust. The difficulty is, propellant is quickly exhausted, leaving the vehicle adrift without any motive power. This makes space travel over long distances extremely difficult.
For example, a rocket traveling to the moon must bring many tons of propellant to both accelerate away from earth and decelerate upon arriving at the moon. Without propellant, the rocket is like the helpless, drifting astronaut discussed above. If there were a way for rockets to propel themselves through space without having to discharge propellant, it would greatly reduce the cost and difficulty of space travel.
Likewise, a satellite orbiting the earth must use tiny retro rockets to change the direction it faces or the manner in which it rotates. When the satellite exhausts its supply of fuel, its orientation can no longer be controlled. When this happens, the satellite is often permanently inoperable. Because millions of dollars are invested in building and launching the satellites, it would be very valuable if satellite life could be prolonged by developing a way to maneuver the satellite without expelling physical propellant.
A similar situation will arise with proposed space stations. For many years, scientists have theorized that a large space station could be built and placed into orbit around the Earth. To simulate earth's gravity for the benefit of the station's occupants, the station would be rotated about a central axis. The centrifugal force experienced by someone at the peripheral of the rotating station would feel like gravity. The difficulty is, the only known way to set a large body such as a space station into spinning motion about its own axis is by placing retrorockets about the station's perimeter, and directing the rockets' thrust in a direction tangential to the desired arc of rotation. Depending on the weight of the station, this process would consume an exorbitant amount of propellant. Ideally there would be a way to spin a space station without using propellant. Although the cost per pound of payload is expected to go down, it is currently at $5,000 to $10,000. Thus, any technique for reducing the amount of propellant required would provide significant savings.
The sheer size of a space station raises other issues akin to the problem of anchoring a tall tower on earth. The station would likely be constructed using long, thin beams on the order of several hundred yards in length. These beams will be prone to vibration (much like the swaying of a tall tower on earth), which could become severe enough to cause structural failure.
Ideally, there would be a way of dampening the movement of vibrating space station beams. Unfortunately, just as the air on earth cannot practically be used to dampen the movement of a swaying tower tip, space offers nothing to "anchor" the vibrating beams. Theoretically, the beams could be equipped with thousands of tiny retrorockets to exert propulsive forces to counteract beam vibration. This solution would be extremely expensive and would necessitate the use of propellant. What is required is a way of imposing a propulsive force on the beams without requiring the expulsion of propellant.
Existing Inertial Attitude Control Devices
It is in fact currently possible to control the rotation of satellites to some extent without having to expel propellant. In accordance with this technique, a flywheel on board the satellite is rotated or accelerated to change or correct the rotational momentum of the satellite. The difficulty with these existing techniques is that once the flywheel is rotated or accelerated, it cannot be returned to its original orientation or speed without offsetting the first change or correction. Thus, existing devices are of limited use.